Related Experiment Video

Updated: Sep 20, 2026

A Phenotyping Regimen for Genetically Modified Mice Used to Study Genes Implicated in Human Diseases of Aging
09:37

A Phenotyping Regimen for Genetically Modified Mice Used to Study Genes Implicated in Human Diseases of Aging

Published on: July 14, 2016

Motor function under lower and higher controlled processing demands in early and continuously treated phenylketonuria

S C J Huijbregts1, L M J De Sonneville, F J Van Spronsen

  • 1Department of Clinical Neuropsychology, Vrije Universiteit Amsterdam, The Netherlands. stephan.huijbregts@umontreal.ca

Neuropsychology
|September 10, 2003
PubMed

Insights

Patients with phenylketonuria (PKU) exhibit impaired motor control, especially younger individuals. These deficits are more pronounced in complex tasks requiring advanced planning and execution, suggesting delayed maturation of motor control systems.

Area of Science:

  • Neuroscience
  • Developmental Psychology
  • Metabolic Disorders

Background:

  • Phenylketonuria (PKU) is a genetic disorder requiring lifelong dietary management.
  • Early and continuous treatment aims to prevent neurological complications.
  • Motor control development is crucial for overall child development.

Purpose of the Study:

  • To investigate motor control abilities in early and continuously treated PKU patients.
  • To compare motor control performance between PKU patients and healthy controls.
  • To explore age-related differences and task-specific deficits in motor control.

Main Methods:

  • A cohort of 61 early and continuously treated PKU patients and 69 controls (aged 7-14) participated.
  • Motor control was assessed using a pursuit task (unpredictable movements) and a tracking task (automated movements).
  • Correlations between motor control performance and historical phenylalanine levels were analyzed.

Main Results:

  • PKU patients demonstrated significantly poorer motor control in both pursuit and tracking tasks compared to controls.
  • Motor deficits were more severe in younger PKU patients (under 11 years).
  • The pursuit task revealed greater deficits in PKU patients than the tracking task, indicating challenges with higher-level cognitive control.

Conclusions:

  • Early and continuous PKU treatment does not fully normalize motor control development.
  • Complex motor tasks requiring controlled processing are particularly challenging for individuals with PKU.
  • Findings suggest a delayed maturation of motor control systems in PKU patients, influenced by phenylalanine exposure.

More Related Videos

Event-related Potentials During Target-response Tasks to Study Cognitive Processes of Upper Limb Use in Children with Unilateral Cerebral Palsy08:26

Event-related Potentials During Target-response Tasks to Study Cognitive Processes of Upper Limb Use in Children with Unilateral Cerebral Palsy

Published on: January 11, 2016

Phenotypic Profiling of MPTP-Induced Parkinsonian-like Behavioral Phenotypes in Zebrafish Larvae Based on Behavioral Experiment10:33

Phenotypic Profiling of MPTP-Induced Parkinsonian-like Behavioral Phenotypes in Zebrafish Larvae Based on Behavioral Experiment

Published on: May 15, 2026

Related Concept Videos

Pharmacokinetics in Pediatric Patients: Drug Metabolism01:24

Pharmacokinetics in Pediatric Patients: Drug Metabolism

In pediatric care, understanding the nuances of hepatic drug metabolism is crucial, as it significantly differs from that of adults. This divergence is primarily due to the developmental stage of drug-metabolizing enzymes, which affects how medications are processed in the body. In neonates, for instance, the activity of Phase I enzymes—critical for the initial breakdown of drugs—is markedly reduced, functioning at just 20–40% of the levels seen in adults. This reduction poses a challenge in...
Overview of Protein Metabolism01:21

Overview of Protein Metabolism

Proteins are broken down into amino acids during digestion. Unlike fats and carbohydrates, which are stored for later use, proteins are not. Instead, amino acids are either used to produce ATP through oxidation or contribute to the creation of new proteins for the growth and repair of the body. Any surplus amino acids from the diet are converted into glucose or triglycerides rather than excreted.
Amino acids play various roles in the body once they are absorbed into cells. They are restructured...
Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase01:27

Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase

Phase II biotransformation reactions are essential for detoxifying and eliminating xenobiotics, including many pharmaceutical compounds. These reactions typically involve conjugation, the covalent attachment of polar endogenous groups such as glucuronic acid, sulfate, methyl, or acetyl moieties to functional groups introduced during Phase I metabolism. The resulting conjugates are more water-soluble, enabling efficient renal or biliary excretion.The major classes of Phase II enzymes include...
Pharmacokinetics in Pediatric Patients: Overview and Drug Absorption01:23

Pharmacokinetics in Pediatric Patients: Overview and Drug Absorption

Understanding the physiological differences in the pediatric population is crucial for effective pharmacotherapy. Neonates, infants, and children exhibit significant variations in gastric pH, gastric emptying time, intestinal transit time, and biliary function. These variations profoundly affect oral drug absorption, necessitating a nuanced approach to pediatric dosing.Neonates present with a unique physiological profile, having a gastric pH greater than 4 and faster and more irregular gastric...
Effect of Hepatic Disease on Pharmacokinetics: Pathophysiologic Assessment and Liver Function Test01:22

Effect of Hepatic Disease on Pharmacokinetics: Pathophysiologic Assessment and Liver Function Test

In clinical practice, the direct measurement of hepatic blood flow to evaluate liver function presents significant challenges due to the intricate and specialized nature of the necessary techniques. Consequently, healthcare professionals often rely on empirical estimates derived from thorough patient examinations and liver function tests to gauge liver health. Among the tools at their disposal, the Child–Pugh and MELD scoring systems stand out for their ability to categorize and assess the...